Magneto-anisotropic weak antilocalization in near-surface quantum wells

TL;DR

This study explores how in-plane magnetic fields affect weak antilocalization in near-surface quantum wells, revealing strong anisotropy due to Rashba and Dresselhaus interactions, with implications for spintronics and quantum computing.

Contribution

It provides a quantitative analysis of spin-orbit coupling parameters and g-factor in quantum wells using a semiclassical model, highlighting the anisotropic magnetoconductivity effects.

Findings

Magnetoconductivity shows strong anisotropy with magnetic field direction.

Rashba and Dresselhaus couplings compete, causing two-fold symmetry.

Anisotropy ratios reach up to 100%, enabling parameter extraction.

Abstract

We investigate the effects of an in-plane magnetic field on the weak antilocalization signature of near-surface quantum wells lacking bulk and inversion symmetry. The measured magnetoconductivity exhibits a strong anisotropy with respect to the direction of the in-plane magnetic field. The two-fold symmetry of the observed magneto-anisotropy originates from the competition between Rashba and Dresselhaus spin-orbit couplings. The high sensitivity of the weak antilocalization to the spin texture produced by the combined Zeeman and spin-orbit fields results in very large anisotropy ratios, reaching 100%. Using a semiclassical universal model in quantitative agreement with the experimental data, we uniquely determine the values of the Dresselhaus and Rashba parameters as well as the effective in-plane g-factor of the electrons. Understanding these parameters provides new prospects for novel applications ranging from spintronics to topological quantum computing.